UART integration

Renode enables exposing emulated UART devices to the host machine and interacting with them using the standard workflow (tools, scripts, etc.) exactly as if they were actual hardware serial ports. This opens the door to designing hybrid setups where part of the system is simulated in Renode and the rest consists of physical devices or software running in the “real world”.

Renode provides two independent mechanisms for exposing virtual UART devices to the host machine:

  • using a pty device (Linux/macOS only),
  • over a network socket (available on all platforms).

UART pty terminal

Note

This feature is available on Linux/macOS only.

UART pty terminal integration allows creating a pty device in the host filesystem that acts as a bridge between the real world and the simulation. Data written to/read from the pty device by the software running in the real world is automatically transferred to the virtual UART device (and vice versa).

In order to expose a virtual UART device, create the UART pty terminal with the following command in the Monitor:

(monitor) emulation CreateUartPtyTerminal "term" "/tmp/uart"

This will create a new file in the host filesystem (/tmp/uart) that can be referenced from within the simulation as term.

Now, connect the newly created UART pty terminal to the simulated UART device:

(machine-0) connector Connect sysbus.uart0 term

Finally, open the terminal application on your host machine (screen/picocom/PuTTY/etc.) and attach it to the /tmp/uart file. You can interact with it just like with the hardware.

Socket terminal

Note

This feature is available on all supported host platforms (Linux/macOS/Windows).

Socket terminal integration allows exposing a virtual UART device over a network socket and making it available for any device in the network. The data sent to the socket available on a selected port number by the software running in the real world (on the local host machine or over the network) is automatically transferred to the virtual UART device (and vice versa).

In order to expose a virtual UART device, create a Socket terminal with the following command in the Monitor:

(monitor) emulation CreateServerSocketTerminal 3456 "term"

This will open a tcp network port 3456 on the host machine that can be referenced from within the simulation as term.

Now, connect the newly created Socket terminal to the simulated UART device:

(machine-0) connector Connect sysbus.uart0 term

Finally, open the terminal application on your host machine (netcat/telnet/PuTTy/etc.) and connect it to port 3456. You can interact with it just like with the hardware.

Emitting configuration bytes

By default Server Socket will emit the following initial configuration bytes in order to properly configure a newly connected terminal:

0xff, 0xfd, 0x00, // IAC DO    BINARY
0xff, 0xfb, 0x01, // IAC WILL  ECHO
0xff, 0xfb, 0x03, // IAC WILL  SUPPRESS_GO_AHEAD
0xff, 0xfc, 0x22  // IAC WONT  LINEMODE

In order to avoid generating them, pass additional False argument when creating the Socket terminal:

(monitor) emulation CreateServerSocketTerminal 3456 "term" False